The present invention relates to attaching a slider to a suspension assembly. More particularly it relates to a gimbal for supporting a slider that provides a direct contact between the gimbal and the slider.
Air bearing sliders have been extensively used in disc drives to appropriately position a transducing head above a rotating disc. The transducing head is typically carried by the slider. Conventionally, head positioning is accomplished by operating an actuator arm with a large-scale actuation motor, such as a voice coil motor (VCM), to radially position the slider on a gimbal at the end of the actuator arm. Typically, disc drive systems include a suspension assembly attached to the actuator arm for supporting and positioning the slider. The suspension assembly includes a load beam attached to the actuator arm and has a gimbal disposed on the other end of the load beam. The air bearing slider carrying the transducing head is mounted to the gimbal. This type of suspension is used with both magnetic and nonmagnetic discs. The VCM rotates the actuator arm and the suspension assembly to position the transducing head over a desired radial track of the disc.
In order for the VCM to correctly position the slider and transducing head over the desired track of the disc, the disc drive communicates with the slider electrically through conductive traces disposed along the suspension assembly. The traces extend along the gimbal and end at gimbal bond pads formed adjacent to the slider. The slider has bond pads disposed on a forward face such that a connection can be made between the traces and the slider.
Difficulties arose in prior art systems for attaching the slider to the gimbal, specifically with vertical alignment of the slider on the gimbal. In particular the slider bond pads should be precisely positioned proximate to the gimbal bond pads so that a connection can be made between the two. One prior art system uses laminated circuit material to provide vertical alignment of the flex circuit to the slider bond pads. Other systems use notches in the slider to allow alignment of the slider with the gimbal bond pads. Some systems use conductive adhesives to reduce the electrical resistance between the slider and the gimbal, but these adhesives did not reduce the area of contact between the gimbal and the slider. The use of conductive adhesives increases the cost and manufacturing time of assembling a slider to a gimbal, whereas the use of laminated circuit material and notches increases the cost of the final assembly and the manufacturing time for the components.
In prior art systems that do not use conductive adhesives, the thick adhesive bond line between the slider and the gimbal increases the electrical resistance between the transducing head and the suspension. The thick adhesive bond line and poor vertical alignment reduces conductivity between the gimbal and slider. Poor conductivity allows a charge to build on the slider, which results in poor electrical performance by increasing the noise in data read by the transducing head. When the layers between the gimbal and slider are large, poor static attitude adjustment results, and in particular poor static attitude control exists over the pitch and roll position of the slider.
A gimbal design is needed in the art for allowing a slider to be attached to a gimbal in a manner that reduces the area of contact between the gimbal and the slider, increases conductivity, improves static attitude control and is more efficient for manufacturing.